The present invention relates to a method whereby the dipeptide sweetener APM may be fixed in a dry, dense condition as part of a stable, granular material that is readily blendable and soluble rendering the APM suitable for use in beverage and like food applications.
The dipeptide sweetener now commonly known as APM and identified generally as the methyl ester of L-aspartyl-L-phenylalanine is estimated to have 100-160 times the sweetness of sucrose on a weight to weight basis. Among the limitations of this dipeptide sweetener are slow rate of dissolution and its limited stability in aqueous systems. The modes of decomposition of APM are not too fully understood but it does appear that the reactions that stem from the presence of APM in moisture lead to an unfavorable interaction with other materials such as aldehydes and ketones and also lead to undesired decomposition products.
A further limitation of APM is the flowability of the dipeptide when intermixed with other powderous materials. The flowability of APM in granular mixtures with citric acid and other beverage mix ingredients is poor in that it tends to bridge the remaining ingredients such that the mix will not flow readily or discharge through high speed packaging equipment; when examined microscopically, APM is seen to cluster as "balls" of needles, no doubt explaining this limitation in product flowability; it is not too clear but it would appear as though there is an electrostatic phenomenon which causes such crystals to intermesh and aggregate. Even when the dipeptide per se is ground or it is coground with other materials serving as dispersants, the ultimate mix produced containing such a composition leaves much to be desired in terms of the flowability thereof by reason of the aforesaid properties of the dipeptide itself; the composition tends to pack or bridge and have a high angle of repose.